Panaeolus punjabensis M. Asif, Q. Firdous, A. Izhar, Niazi & Khalid sp. nov. was collected from three different localities (Bahawalnagar, Kasur, and Lahore) in Punjab, Pakistan. Morphological observations phylogenetic analyses based on nuclear encoded internal transcribed spacers (ITS1-5.8S-ITS2 = ITS) D1/D2 domain of large subunit (28S) rDNA confirmed the taxonomic distinctness this specie...

Multicopy genes, like ribosomal RNA genes (rDNA), are widely used to describe and distinguish individuals. Despite concerted evolution that homogenizes a large number of rDNA gene copies, the presence of different gene variants within a genome has been reported. Characterization of an organism by defining every single variant of tens to thousands of rDNA repeat units present in a eukaryotic gen...

Detailed analysis of variation in intergenic spacer (IGS) and internal transcribed spacer (ITS) regions of rDNA drawn from natural populations of Drosophila melanogaster has revealed contrasting patterns of homogenization although both spacers are located in the same rDNA unit. On the basis of the role of IGS regions in X-Y chromosome pairing, we proposed a mechanism of single-strand exchanges ...

Ribosomal DNA (rDNA) from Xenopus laevis contains several heterogeneities in all three transcribed spacers, as revealed by analysis of cloned and uncloned amplified rDNA from oocytes and cloned chromosomal rDNA from erythrocytes. Heterogeneities include single base changes and length variants of one to several nucleotides. Sites of variation are widely but non-uniformly distributed, some occurr...

Rhizoctonia solani (Kuhn) is one of the most important cotton crop pathogens. Rhizoctonia solani anastomosis groups (AGs) 7 and 4 are proven to be the most common pathogenic fungal strains on cotton crop. AG-7 can cause root rot in plants while damping-off of seedlings is most frequently attributed to AG-4. Sequencing of the ITS (Internal Transcribed Spacer) region of ribosomal DNA was performe...

background and purpose: by using advanced detection/identification methods, the list of emerging uncommon opportunistic yeast infections is rapidly expanding worldwide. our aim in the present study was sequence-based species delineation of previously unidentified yeasts obtained from a clinically yeast collection. materials and methods: a total of twenty three out of the 855 (5.7%) yeast isolat...

rDNA structure. The nucleus is a highly organized structure. However, unlike cytoplasmic organelles, nuclear substructures are not bounded by membranes, but rather are held together by interactions between their component proteins and nucleic acids, and are thus probably best regarded as giant, extended multi-molecular complexes. The nucleolus is the most prominent of these structures. It is th...

Phylogenetic and genetic relationships among 10 North American Armillaria species were analysed using sequence data from ribosomal DNA (rDNA), including intergenic spacer (IGS-1), internal transcribed spacers with associated 5.8S (ITS + 5.8S), and nuclear large subunit rDNA (nLSU), and amplified fragment length polymorphism (AFLP) markers. Based on rDNA sequence data, the nLSU region is less va...

Ribosomal DNA (rDNA) sequence data were compared for five species of Globodera, including G. rostochiensis, G. pallida, G. virginiae, and two undescribed Globodera isolates from Mexico collected from weed species and maintained on Solanum dulcamara. The rDNA comparisons included both internal transcribed spacers (ITS1 and ITS2), the 5.8S rRNA gene, and small portions of the 3' end of the 18S ge...